Development of Small-sized and Simplified Sinker Electrical Discharge Machining (EDM) Machine Hiroyuki Kido Tsukuba University of Technology Course of Design/Process Systems Department of Industrial Information Division of Industrial Technology 1

2 Electrical Discharge Machining (EDM) Electrically isolated Arc Vaporization Removed Material Pressur e EDM is a non-contact type method of thermal machining using electricity, and thus EDM can work irrespective of the hardness of workpiece. EDM is regarded as one of special machining methods. Figure 1 Machining Process

Objectives 3 Develop and operate a machine using an unique machining method of EDM. Understand the mechanism and principle of EDM Apply the research results to actual manufacturing.

Assembly of Small-sized and Simplified EDM (SSEDM) 4 1Clean damper 2Stepping motor 3Displacement gauge 4Coupling 5Threaded shaft 6Shank holder 7Motor bracket 8Slide 9Stage 10Vise Figure 2 Assembly Drawing of SSEDM

Overview of SSEDM 5 EDM Machine Control Panel Ion Exchange Unit ＊ Figure 3 Overview of SSEDM ＊ Reference ： Manufacture of de-ionized water circulation system ： Wataru Nozoe ： System Technology Special Research ： 2010

6 Main Control Items Figure 4 Control Panel Drive Frequency Base VoltageMotor Connection Power Connection Power Stop Up Down Acceleration Base Voltage Check Drive Frequency Check Contact Detection Servo Control Semi-auto Control Drive Signal

7 Figure 6 Contact Detection Stop Figure 5 Servo Control To slide the electrode up and down to keep the machining voltage equal to the base voltage. Figure 7 Semi-auto Control Main Control Items To see how many mm the electrode was consumed by. (1)Servo Control (2) Contact Detection (3) Semi-auto Control

Machining Mechanism 8 Workpiece Figure 8 Machining Mechanism Electrode Mirror

Trial Machining 9 Figure 10 Machining Result Figure 9 Machining Situation Machining Eccentricity ・ Workpiece ： Stainless Steel Pipe with a diameter of 1.5 mm ・ Electrode ： Lead for Mechanical Pencil ・ Machining Time ： 51sec. Crushing

10 Summary A small-sized EDM machine (SSEDM) was developed. SSEDM performed machining with small dimension.